Example

Example: Evaluating the Function g(x)=3x5g(x) = 3x - 5

To evaluate the linear function g(x)=3x5g(x) = 3x - 5 for specific algebraic expressions, substitute each expression for the independent variable xx and simplify using the order of operations:

  • Evaluate g(h2)g(h^2): Replace xx with h2h^2 to get g(h2)=3(h2)5g(h^2) = 3(h^2) - 5. Simplify to yield g(h2)=3h25g(h^2) = 3h^2 - 5.
  • Evaluate g(x+2)g(x+2): Replace xx with the binomial (x+2)(x+2) using parentheses to get g(x+2)=3(x+2)5g(x+2) = 3(x+2) - 5. Distribute the 33 to obtain 3x+653x + 6 - 5. Simplify by combining the constant terms to find g(x+2)=3x+1g(x+2) = 3x + 1.
  • Evaluate g(x)+g(2)g(x) + g(2): This expression requires finding the value of g(2)g(2) first and adding it to the expression for g(x)g(x). Find g(2)=3(2)5=65=1g(2) = 3(2) - 5 = 6 - 5 = 1. Then, substitute both parts into the sum to get g(x)+g(2)=(3x5)+(1)g(x) + g(2) = (3x - 5) + (1). Simplify by combining the constant terms to find g(x)+g(2)=3x4g(x) + g(2) = 3x - 4.

Notice that evaluating a sum, such as g(x+2)g(x+2), is not necessarily equal to the sum of the evaluated function values, g(x)+g(2)g(x) + g(2).

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Updated 2026-05-06

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